【摘要】 本文是前两项工作的继续,采用微震仪记录图测定了张家口—怀柔地区微震（M_L=2.0—3.0）的震源参数,结果表明,拐角频率在2—5赫兹范围,地震矩为（0.5—20）×10¹⁹达因·厘米数量级,应力降为十分之几巴到几巴.更多还原

【Abstract】 The present paper is the continuation of two previous ones. The focal para-meters of microearthquakes （M_L = 2.0-3.0） recorded in the Zhangjiakou-Huairou re-gion have been determined from seismograms. The results are: corner frequenciesrange from 2-5 Hz; seismic moment varies between （0.5-20） × 10¹⁹ dyne·cm;stress drops are estimated to be less than one to few bars.更多还原